JPH0315722Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an extendable mast that can be shortened into a coiled shape and becomes a truss-like column when extended.

This type of mast is conventionally known (see, for example, Japanese Patent Publication No. 49-26653), and is used as antenna masts for artificial satellites.

FIG. 1 shows a main body part 1 of a known extendable mast, in which 2 is a stringer made of a flexible material such as glass fiber, and 3 is a stringer that interconnects three stringers. It is a horizontal member, and the contact point 4 between the stringer 2 and the horizontal member 3
A rotary joint (not shown) is placed in each of the parts. 5 is a tension cable connecting the contact points diagonally, and 6 is a tightening cable passing through the center of the mast. Each of the horizontal members 3 is made up of three rods, but these can be replaced by members 3' shaped as shown by chain lines in FIG.

When retracting this mast, the tightening rope 6 is pulled to compress the mast in the longitudinal direction. Then, as shown in FIG. 3, the stringer 2 is deformed into a coil shape, and the entire mast contracts. Conversely, when the tightening rope 6 is loosened, the mast will extend to its original length. However, if it is completely retracted as shown in FIG. 4, it goes without saying that the mast will not extend just by loosening the tie rope 6.

For this reason, in the conventional mast, the lower part of the stringer 2 is actually vertically fixed to the storage case 7 with a fixing fitting 8, as shown in FIG. Therefore,
Once the tie rope 6 is loosened, the diagonal part 2 of the stringer 2
The mast can be raised by the strain energy stored in a. However, if you do it like this,
Since there is a portion at the bottom of the mast that cannot be folded, there is a problem that the storage volume of the mast, that is, the case 7 cannot be reduced.

The purpose of this invention is to obtain an extendable mast that can solve these problems.

Next, this invention will be explained based on the drawings. As shown in FIG. 6, the extendable mast of this invention has a main body 1 having a structure similar to that described above. However, so that the stringer 2 can be folded downward into a coil shape as shown in FIG. It is pivoted.

In addition, in the mast of this invention, among the many contact points 4, the lowest one 4a of each stringer 2 is used to extend the mast.
It has a guide along the trajectory drawn during contraction.
In the embodiment, this guide is constituted by a slit 10 made in the circumferential surface of the storage case 7. In addition, as shown in detail in FIG. 8, the lowermost contact 4a
A pin 11 extending from is fitted.

Furthermore, the mast of this invention has a means for forcibly pulling up the lowermost contact point 4a along the guide, and this may be made of rubber or the like, but in this embodiment it is constituted by a coil spring 12. This spring 12
extends into a semicircular cover 13 attached to the outer surface of the storage case 7 so as to cover the slit 10, and its one end is fixed to the aforementioned pin 11 and the other end is fixed to a fixed point on the storage case 7. It is worn.

14 is a latch that is hung on the pin 11 when the lower part of the stringer 2 stands up vertically. others,
15 is a motor, and 16 is a tower-mounted object at the end of the mast.

With this structure, if the motor 15 is driven to wind up the tightening rope 6 in the state shown in FIG. 6, the mast body 1 will contract into a coil shape as described above.
Moreover, since the lower end of the stringer 2 is pivotally connected by a pin 11, the entire mast body 1 is wound in a coiled manner up to the lower part, as shown in FIG. Therefore, the mast body 1 fits into a smaller storage case 7 than in the conventional case (FIG. 5).

When the mast body contracts in this manner, the lowermost contact 4a moves downward along the slit 10, so that the coil spring 12 is stretched. Therefore, when the tightening cable 6 is now loosened from the state shown in FIG.
Along with this, the stringer 2 rises around the pin 9. When the lower part of the stringer 2 rises vertically, the latch 14 is placed on the pin 11. This state is the same as the state shown in FIG. 5, and if the tightening rope 6 is further loosened, the mast will extend upward.

As explained above, this idea provides a guide that matches the trajectory drawn by the lowest contact point when the mast expands and contracts, and the lowest contact point is pulled up along this guide, so only a small amount of force is required. The mast can be raised reliably. What's more, the mast body can be folded up to the bottom in a coiled manner, making it possible to store it in a small container.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the extensible mast body, Figure 2 is a sectional view of the mast, Figure 3 is a perspective view of the extensible mast body in the middle of extension or contraction, and Figure 4 is a fully retracted extensible mast body. 5 is a perspective view of a conventional extendable mast in a contracted state; FIG. 6 is a perspective view of the extendable mast according to this invention in an extended state; FIG. 7 is a perspective view of the same mast in a contracted state; FIG. is a cross-sectional view of the slit. 2... Longer members, 3, 3'... Transverse members, 4... Contacts, 5... Tension cables, 10... Slits as guides, 11... Pins, 12... Coil springs as pulling means.

Claims (1)

[Claims for Utility Model Registration] 1. At least three stringers, a plurality of transverse members interconnecting these stringers, and a plurality of tension members diagonally connecting the contact points of these stringers and transverse members. In an extensible mast, which consists of a cable, when compressed in the longitudinal direction, the stringer coils and contracts, and the lower end of the stringer is placed on an external fixing base so that the lower part of the stringer collapses laterally. An extendable mast that is pivotally mounted and has a guide that corresponds to the locus drawn by the lowermost contact point during extension or contraction, and has means for forcibly pulling up the lowermost contact point along this guide during extension. . 2. The utility model registration claim 1, wherein the guide is a slit made in the circumferential surface of a cylindrical case housing the mast, and a pin extending from the lowermost contact point is engaged with the slit. Extended mast. 3. The extendable mast according to claim 1 or 2, wherein the lifting means is a coil spring extending along the guide between the lowermost contact point and an external fixing point.